One Baháʼí scholar states that it can be regarded as the "most influential Quran commentary in Persian outside the Muslim world," because of its international audience.
The uncle of the Báb, Ḥájí Mírzá Siyyid Muḥammad, had been perplexed to hear that the promised one of Islam was his own nephew.
Since the questioner is a Muslim, Baháʼu'lláh uses verses from the Bible to show how a Christian could interpret his own sacred texts in allegorical terms to come to believe in the next religion.
The second and longer part of the book is the substantive discourse and deals with specific proofs, both theological and logical, of the mission of the Báb.
Shoghi Effendi gave the following lengthy description of the book's content:Within a compass of two hundred pages it proclaims unequivocally the existence and oneness of a personal God, unknowable, inaccessible, the source of all Revelation, eternal, omniscient, omnipresent and almighty; asserts the relativity of religious truth and the continuity of Divine Revelation; affirms the unity of the Prophets, the universality of their Message, the identity of their fundamental teachings, the sanctity of their scriptures, and the twofold character of their stations; denounces the blindness and perversity of the divines and doctors of every age; cites and elucidates the allegorical passages of the New Testament, the abstruse verses of the Quran, and the cryptic Muhammadan traditions which have bred those age-long misunderstandings, doubts and animosities that have sundered and kept apart the followers of the world's leading religious systems; enumerates the essential prerequisites for the attainment by every true seeker of the object of his quest; demonstrates the validity, the sublimity and significance of the Báb's Revelation; acclaims the heroism and detachment of His disciples; foreshadows, and prophesies the world-wide triumph of the Revelation promised to the people of the Bayán; upholds the purity and innocence of the Virgin Mary; glorifies the Imams of the Faith of Muhammad; celebrates the martyrdom, and lauds the spiritual sovereignty, of the Imam Husayn; unfolds the meaning of such symbolic terms as "Return," "Resurrection," "Seal of the Prophets" and "Day of Judgment"; adumbrates and distinguishes between the three stages of Divine Revelation; and expatiates, in glowing terms, upon the glories and wonders of the "City of God," renewed, at fixed intervals, by the dispensation of Providence, for the guidance, the benefit and salvation of all mankind.
Shoghi Effendi, head of the Baháʼí Faith from 1921 to 1957, referred to the work as follows: A model of Persian prose, of a style at once original, chaste and vigorous, and remarkably lucid, both cogent in argument and matchless in its irresistible eloquence, this Book, setting forth in outline the Grand Redemptive Scheme of God, occupies a position unequalled by any work in the entire range of Baháʼí literature, except the Kitáb-i-Aqdas, Baháʼu'lláh's Most Holy Book.